Alert archive / New Jersey / Flash Flood Warnings in 2021

Flash Flood Warning 52, NWS Philadelphia/Mount Holly

August 22, 2021Monmouth County, Ocean County, New Jersey

NWS Philadelphia/Mount Holly issued this flash flood warning at Aug 22, 2021, 4:21 AM EDT for Monmouth County, Ocean County, New Jersey. It was in force for 3 hr. 2 reports came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued: Aug 22, 2021, 4:21 AM EDT (08:21 UTC)
Expired: Aug 22, 2021, 6:52 AM EDT
In force: 3 hr
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Flood severity: None

Counties Monmouth County, NJ, Ocean County, NJ

The radar

The Philadelphia radar (KDIX), 51 km from the middle of the area, began a volume at 08:24 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

What was reported inside it

Time	Report	Where	Remark
Aug 22, 6:14 AM EDT	HEAVY RAIN 2.51	2 Sse Howell, NJ	COCORAHS STATION NJ-MN-64 HOWELL TWP 3.7 SSW.
Aug 22, 7:00 AM EDT	HEAVY RAIN 1.15	1 Nnw Brielle, NJ	COCORAHS STATION NJ-MN-75 MANASQUAN 1 WNW.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Brookhaven, NY (KOKX), launched 00:00Z, 8.4 hours before the alert went out and 118 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.

Mixed-layer CAPE: 1163 J/kg
Mixed-layer CIN: -6 J/kg
Mixed-layer LCL: 543 m above ground
0-6 km bulk shear: 21 kt
0-1 km storm-relative helicity: 75 m²/s²
0-3 km storm-relative helicity: 85 m²/s²
Significant tornado parameter: 0.3
Supercell composite: 1.7

Open this sounding in Storm Lab

The text

As transmitted.

349 
WGUS51 KPHI 220821
FFWPHI
NJC025-029-221300-
/O.NEW.KPHI.FF.W.0052.210822T0821Z-210822T1300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Mount Holly NJ
421 AM EDT Sun Aug 22 2021

The National Weather Service in Mount Holly has issued a

* Flash Flood Warning for...
  Southeastern Monmouth County in central New Jersey...
  Northeastern Ocean County in southern New Jersey...

* Until 900 AM EDT.

* At 421 AM EDT, Doppler radar indicated heavy rain across the 
  warned area. Between 1 and 2 inches of rain have already fallen in 
  spots. Additional rainfall amounts of 1 to 3 inches are possible 
  in the warned area. Flash flooding is ongoing or expected to begin 
  shortly.

  HAZARD...Flash flooding caused by heavy rain.

  SOURCE...Radar.

  IMPACT...Flooding of small creeks and streams, urban areas,
           highways, streets, and underpasses as well as other
           drainage and low lying areas.

* Some locations that will experience flash flooding include...
  Toms River, Long Branch, Asbury Park, Sandy Hook, Lakewood, 
  Jackson, Howell, Tinton Falls, Beachwood, Manasquan, Point 
  Pleasant Beach, and Seaside Heights.

This includes the following highways...
	Interstate 195 in New Jersey between mile markers 23 and 34.
	Garden State Parkway between mile markers 78 and 104.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Motorists should not attempt to drive around barricades or drive 
cars through flooded areas.

&&

LAT...LON 4026 7427 4024 7409 4033 7403 4042 7405
      4040 7398 4043 7399 4042 7399 4042 7400
      4045 7399 4048 7401 4047 7400 4044 7398
      4041 7393 4036 7392 4006 7402 3969 7410
      4012 7433

FLASH FLOOD...RADAR INDICATED

$$

Iovino

1 follow-up statement

911 
WGUS71 KPHI 221052
FFSPHI

Flash Flood Statement
National Weather Service Mount Holly NJ
652 AM EDT Sun Aug 22 2021

NJC025-029-221102-
/O.CAN.KPHI.FF.W.0052.000000T0000Z-210822T1300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Monmouth NJ-Ocean NJ-
652 AM EDT Sun Aug 22 2021

...FLASH FLOOD WARNING IS CANCELLED FOR SOUTHEASTERN MONMOUTH AND 
NORTHEASTERN OCEAN COUNTIES...

The heavy rain has ended. Flooding is no longer expected to pose a 
threat. Please continue to heed remaining road closures.

A Flood Watch remains in effect until 800 AM Monday.

LAT...LON 4026 7427 4024 7409 4033 7403 4042 7405
      4040 7398 4043 7399 4042 7399 4042 7400
      4045 7399 4048 7401 4047 7400 4044 7398
      4041 7393 4036 7392 4006 7402 3969 7410
      4012 7433

$$

Iovino

The office that day

Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Aug 21, 9:35 PM EDT	Areal Flood Advisory	PHI	Mercer, Middlesex, Monmouth, Ocean	3 hr
Aug 21, 10:47 PM EDT	Areal Flood Advisory	PHI	Morris	3 hr
Aug 21, 11:38 PM EDT	Areal Flood Advisory	PHI	Atlantic, Burlington, Monmouth, Ocean	3 hr
Aug 22, 12:04 AM EDT	Areal Flood Advisory	PHI	Atlantic, Burlington, Camden, Monmouth, Ocean	3 hr
Aug 22, 12:24 AM EDT	Flash Flood Warning	PHI	Morris	3 hr
Aug 22, 1:30 AM EDT	Areal Flood Advisory	PHI	Middlesex, Monmouth	4 hr
Aug 22, 1:35 AM EDT	Areal Flood Advisory	PHI	Morris, Somerset	3 hr
Aug 22, 2:04 AM EDT	Flash Flood Warning	PHI	Middlesex, Monmouth	9 hr
Aug 22, 2:09 AM EDT	Flash Flood Warning	PHI	Burlington, Ocean	5 hr
Aug 22, 2:40 AM EDT	Flash Flood Warning	PHI	Hunterdon, Morris, Somerset	5 hr
Aug 22, 3:10 AM EDT	Flash Flood Warning	PHI	Burlington, Hunterdon, Mercer, Monmouth, Ocean	8 hr
Aug 22, 5:36 AM EDT	Flash Flood Warning Considerable damage threat	PHI	Mercer, Middlesex, Monmouth, Somerset	5 hr
Aug 22, 6:07 AM EDT	Flash Flood Warning	PHI	Hunterdon, Warren	67 min
Aug 22, 7:52 AM EDT	Areal Flood Warning	PHI	Hunterdon, Somerset	15 hr
Aug 22, 10:43 AM EDT	Special Marine Warning	PHI		62 min
Aug 22, 10:49 AM EDT	Areal Flood Warning	PHI	Middlesex, Monmouth, Somerset	13 hr
Aug 22, 10:52 AM EDT	Areal Flood Warning	PHI	Hunterdon, Mercer, Monmouth	13 hr
Aug 22, 11:06 AM EDT	Special Marine Warning	PHI		54 min
Aug 22, 1:35 PM EDT	Coastal Flood Advisory	PHI	Cape May	10 hr
Aug 22, 1:53 PM EDT	Areal Flood Advisory	PHI	Morris	6 hr
Aug 22, 3:21 PM EDT	River Flood Warning	PHI	Somerset	54 hr
Aug 22, 5:07 PM EDT	Areal Flood Advisory	PHI	Morris, Sussex, Warren	6 hr
Aug 22, 5:48 PM EDT	Flash Flood Warning	PHI	Morris, Sussex, Warren	6 hr

Nearby

Flash Flood Warnings in New Jersey, 2021 Every flash flood warning in 2021

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.